| Message ID | 20210725055458.29008-2-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/8] block: make the block holder code optional | expand |
On Sun, Jul 25 2021 at 1:54P -0400, Christoph Hellwig <hch@lst.de> wrote: > Move the block holder code into a separate file as it is not in any way > related to the other block_dev.c code, and add a new selectable config > option for it so that we don't have to build it without any remapped > drivers selected. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > block/Kconfig | 4 ++ > block/Makefile | 1 + > block/holder.c | 139 ++++++++++++++++++++++++++++++++++++ > drivers/md/Kconfig | 2 + > drivers/md/bcache/Kconfig | 1 + > fs/block_dev.c | 144 +------------------------------------- > include/linux/blk_types.h | 2 +- > include/linux/genhd.h | 4 +- > 8 files changed, 151 insertions(+), 146 deletions(-) > create mode 100644 block/holder.c > > diff --git a/block/Kconfig b/block/Kconfig > index fd732aede922..a24d7263d1fc 100644 > --- a/block/Kconfig > +++ b/block/Kconfig > @@ -251,4 +251,8 @@ config BLK_MQ_RDMA > config BLK_PM > def_bool BLOCK && PM > > +# do not use in new code > +config BLOCK_HOLDER_DEPRECATED > + bool > + What is it that new code that does IO remapping and device stacking _should_ be using!? Seems the whole "do not use" and "DEPRECATED" is a misnomer. But those nits aside, code looks fine mechnically: Reviewed-by: Mike Snitzer <snitzer@redhat.com> > source "block/Kconfig.iosched" > diff --git a/block/Makefile b/block/Makefile > index bfbe4e13ca1e..6fc6216634ed 100644 > --- a/block/Makefile > +++ b/block/Makefile > @@ -42,3 +42,4 @@ obj-$(CONFIG_BLK_SED_OPAL) += sed-opal.o > obj-$(CONFIG_BLK_PM) += blk-pm.o > obj-$(CONFIG_BLK_INLINE_ENCRYPTION) += keyslot-manager.o blk-crypto.o > obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) += blk-crypto-fallback.o > +obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED) += holder.o > diff --git a/block/holder.c b/block/holder.c > new file mode 100644 > index 000000000000..904a1dcd5c12 > --- /dev/null > +++ b/block/holder.c > @@ -0,0 +1,139 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +#include <linux/genhd.h> > + > +struct bd_holder_disk { > + struct list_head list; > + struct gendisk *disk; > + int refcnt; > +}; > + > +static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, > + struct gendisk *disk) > +{ > + struct bd_holder_disk *holder; > + > + list_for_each_entry(holder, &bdev->bd_holder_disks, list) > + if (holder->disk == disk) > + return holder; > + return NULL; > +} > + > +static int add_symlink(struct kobject *from, struct kobject *to) > +{ > + return sysfs_create_link(from, to, kobject_name(to)); > +} > + > +static void del_symlink(struct kobject *from, struct kobject *to) > +{ > + sysfs_remove_link(from, kobject_name(to)); > +} > + > +/** > + * bd_link_disk_holder - create symlinks between holding disk and slave bdev > + * @bdev: the claimed slave bdev > + * @disk: the holding disk > + * > + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. > + * > + * This functions creates the following sysfs symlinks. > + * > + * - from "slaves" directory of the holder @disk to the claimed @bdev > + * - from "holders" directory of the @bdev to the holder @disk > + * > + * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is > + * passed to bd_link_disk_holder(), then: > + * > + * /sys/block/dm-0/slaves/sda --> /sys/block/sda > + * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 > + * > + * The caller must have claimed @bdev before calling this function and > + * ensure that both @bdev and @disk are valid during the creation and > + * lifetime of these symlinks. > + * > + * CONTEXT: > + * Might sleep. > + * > + * RETURNS: > + * 0 on success, -errno on failure. > + */ > +int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) > +{ > + struct bd_holder_disk *holder; > + int ret = 0; > + > + mutex_lock(&bdev->bd_disk->open_mutex); > + > + WARN_ON_ONCE(!bdev->bd_holder); > + > + /* FIXME: remove the following once add_disk() handles errors */ > + if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) > + goto out_unlock; > + > + holder = bd_find_holder_disk(bdev, disk); > + if (holder) { > + holder->refcnt++; > + goto out_unlock; > + } > + > + holder = kzalloc(sizeof(*holder), GFP_KERNEL); > + if (!holder) { > + ret = -ENOMEM; > + goto out_unlock; > + } > + > + INIT_LIST_HEAD(&holder->list); > + holder->disk = disk; > + holder->refcnt = 1; > + > + ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); > + if (ret) > + goto out_free; > + > + ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); > + if (ret) > + goto out_del; > + /* > + * bdev could be deleted beneath us which would implicitly destroy > + * the holder directory. Hold on to it. > + */ > + kobject_get(bdev->bd_holder_dir); > + > + list_add(&holder->list, &bdev->bd_holder_disks); > + goto out_unlock; > + > +out_del: > + del_symlink(disk->slave_dir, bdev_kobj(bdev)); > +out_free: > + kfree(holder); > +out_unlock: > + mutex_unlock(&bdev->bd_disk->open_mutex); > + return ret; > +} > +EXPORT_SYMBOL_GPL(bd_link_disk_holder); > + > +/** > + * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() > + * @bdev: the calimed slave bdev > + * @disk: the holding disk > + * > + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. > + * > + * CONTEXT: > + * Might sleep. > + */ > +void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) > +{ > + struct bd_holder_disk *holder; > + > + mutex_lock(&bdev->bd_disk->open_mutex); > + holder = bd_find_holder_disk(bdev, disk); > + if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { > + del_symlink(disk->slave_dir, bdev_kobj(bdev)); > + del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); > + kobject_put(bdev->bd_holder_dir); > + list_del_init(&holder->list); > + kfree(holder); > + } > + mutex_unlock(&bdev->bd_disk->open_mutex); > +} > +EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); > diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig > index 0602e82a9516..f821dae101a9 100644 > --- a/drivers/md/Kconfig > +++ b/drivers/md/Kconfig > @@ -15,6 +15,7 @@ if MD > > config BLK_DEV_MD > tristate "RAID support" > + select BLOCK_HOLDER_DEPRECATED if SYSFS > help > This driver lets you combine several hard disk partitions into one > logical block device. This can be used to simply append one > @@ -201,6 +202,7 @@ config BLK_DEV_DM_BUILTIN > > config BLK_DEV_DM > tristate "Device mapper support" > + select BLOCK_HOLDER_DEPRECATED if SYSFS > select BLK_DEV_DM_BUILTIN > depends on DAX || DAX=n > help > diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig > index d1ca4d059c20..cf3e8096942a 100644 > --- a/drivers/md/bcache/Kconfig > +++ b/drivers/md/bcache/Kconfig > @@ -2,6 +2,7 @@ > > config BCACHE > tristate "Block device as cache" > + select BLOCK_HOLDER_DEPRECATED if SYSFS > select CRC64 > help > Allows a block device to be used as cache for other devices; uses > diff --git a/fs/block_dev.c b/fs/block_dev.c > index 0c424a0cadaa..7825d152634e 100644 > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -900,7 +900,7 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) > bdev->bd_disk = disk; > bdev->bd_partno = partno; > bdev->bd_inode = inode; > -#ifdef CONFIG_SYSFS > +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED > INIT_LIST_HEAD(&bdev->bd_holder_disks); > #endif > bdev->bd_stats = alloc_percpu(struct disk_stats); > @@ -1092,148 +1092,6 @@ void bd_abort_claiming(struct block_device *bdev, void *holder) > } > EXPORT_SYMBOL(bd_abort_claiming); > > -#ifdef CONFIG_SYSFS > -struct bd_holder_disk { > - struct list_head list; > - struct gendisk *disk; > - int refcnt; > -}; > - > -static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, > - struct gendisk *disk) > -{ > - struct bd_holder_disk *holder; > - > - list_for_each_entry(holder, &bdev->bd_holder_disks, list) > - if (holder->disk == disk) > - return holder; > - return NULL; > -} > - > -static int add_symlink(struct kobject *from, struct kobject *to) > -{ > - return sysfs_create_link(from, to, kobject_name(to)); > -} > - > -static void del_symlink(struct kobject *from, struct kobject *to) > -{ > - sysfs_remove_link(from, kobject_name(to)); > -} > - > -/** > - * bd_link_disk_holder - create symlinks between holding disk and slave bdev > - * @bdev: the claimed slave bdev > - * @disk: the holding disk > - * > - * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. > - * > - * This functions creates the following sysfs symlinks. > - * > - * - from "slaves" directory of the holder @disk to the claimed @bdev > - * - from "holders" directory of the @bdev to the holder @disk > - * > - * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is > - * passed to bd_link_disk_holder(), then: > - * > - * /sys/block/dm-0/slaves/sda --> /sys/block/sda > - * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 > - * > - * The caller must have claimed @bdev before calling this function and > - * ensure that both @bdev and @disk are valid during the creation and > - * lifetime of these symlinks. > - * > - * CONTEXT: > - * Might sleep. > - * > - * RETURNS: > - * 0 on success, -errno on failure. > - */ > -int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) > -{ > - struct bd_holder_disk *holder; > - int ret = 0; > - > - mutex_lock(&bdev->bd_disk->open_mutex); > - > - WARN_ON_ONCE(!bdev->bd_holder); > - > - /* FIXME: remove the following once add_disk() handles errors */ > - if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) > - goto out_unlock; > - > - holder = bd_find_holder_disk(bdev, disk); > - if (holder) { > - holder->refcnt++; > - goto out_unlock; > - } > - > - holder = kzalloc(sizeof(*holder), GFP_KERNEL); > - if (!holder) { > - ret = -ENOMEM; > - goto out_unlock; > - } > - > - INIT_LIST_HEAD(&holder->list); > - holder->disk = disk; > - holder->refcnt = 1; > - > - ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); > - if (ret) > - goto out_free; > - > - ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); > - if (ret) > - goto out_del; > - /* > - * bdev could be deleted beneath us which would implicitly destroy > - * the holder directory. Hold on to it. > - */ > - kobject_get(bdev->bd_holder_dir); > - > - list_add(&holder->list, &bdev->bd_holder_disks); > - goto out_unlock; > - > -out_del: > - del_symlink(disk->slave_dir, bdev_kobj(bdev)); > -out_free: > - kfree(holder); > -out_unlock: > - mutex_unlock(&bdev->bd_disk->open_mutex); > - return ret; > -} > -EXPORT_SYMBOL_GPL(bd_link_disk_holder); > - > -/** > - * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() > - * @bdev: the calimed slave bdev > - * @disk: the holding disk > - * > - * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. > - * > - * CONTEXT: > - * Might sleep. > - */ > -void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) > -{ > - struct bd_holder_disk *holder; > - > - mutex_lock(&bdev->bd_disk->open_mutex); > - > - holder = bd_find_holder_disk(bdev, disk); > - > - if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { > - del_symlink(disk->slave_dir, bdev_kobj(bdev)); > - del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); > - kobject_put(bdev->bd_holder_dir); > - list_del_init(&holder->list); > - kfree(holder); > - } > - > - mutex_unlock(&bdev->bd_disk->open_mutex); > -} > -EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); > -#endif > - > static void blkdev_flush_mapping(struct block_device *bdev) > { > WARN_ON_ONCE(bdev->bd_holders); > diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h > index 290f9061b29a..7a4e139d24ef 100644 > --- a/include/linux/blk_types.h > +++ b/include/linux/blk_types.h > @@ -34,7 +34,7 @@ struct block_device { > void * bd_holder; > int bd_holders; > bool bd_write_holder; > -#ifdef CONFIG_SYSFS > +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED > struct list_head bd_holder_disks; > #endif > struct kobject *bd_holder_dir; > diff --git a/include/linux/genhd.h b/include/linux/genhd.h > index 13b34177cc85..6831d74f2002 100644 > --- a/include/linux/genhd.h > +++ b/include/linux/genhd.h > @@ -316,7 +316,7 @@ void set_capacity(struct gendisk *disk, sector_t size); > int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long); > long compat_blkdev_ioctl(struct file *, unsigned, unsigned long); > > -#ifdef CONFIG_SYSFS > +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED > int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk); > void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk); > #else > @@ -329,7 +329,7 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev, > struct gendisk *disk) > { > } > -#endif /* CONFIG_SYSFS */ > +#endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */ > > dev_t part_devt(struct gendisk *disk, u8 partno); > dev_t blk_lookup_devt(const char *name, int partno); > -- > 2.30.2 >
diff --git a/block/Kconfig b/block/Kconfig index fd732aede922..a24d7263d1fc 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -251,4 +251,8 @@ config BLK_MQ_RDMA config BLK_PM def_bool BLOCK && PM +# do not use in new code +config BLOCK_HOLDER_DEPRECATED + bool + source "block/Kconfig.iosched" diff --git a/block/Makefile b/block/Makefile index bfbe4e13ca1e..6fc6216634ed 100644 --- a/block/Makefile +++ b/block/Makefile @@ -42,3 +42,4 @@ obj-$(CONFIG_BLK_SED_OPAL) += sed-opal.o obj-$(CONFIG_BLK_PM) += blk-pm.o obj-$(CONFIG_BLK_INLINE_ENCRYPTION) += keyslot-manager.o blk-crypto.o obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) += blk-crypto-fallback.o +obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED) += holder.o diff --git a/block/holder.c b/block/holder.c new file mode 100644 index 000000000000..904a1dcd5c12 --- /dev/null +++ b/block/holder.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/genhd.h> + +struct bd_holder_disk { + struct list_head list; + struct gendisk *disk; + int refcnt; +}; + +static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, + struct gendisk *disk) +{ + struct bd_holder_disk *holder; + + list_for_each_entry(holder, &bdev->bd_holder_disks, list) + if (holder->disk == disk) + return holder; + return NULL; +} + +static int add_symlink(struct kobject *from, struct kobject *to) +{ + return sysfs_create_link(from, to, kobject_name(to)); +} + +static void del_symlink(struct kobject *from, struct kobject *to) +{ + sysfs_remove_link(from, kobject_name(to)); +} + +/** + * bd_link_disk_holder - create symlinks between holding disk and slave bdev + * @bdev: the claimed slave bdev + * @disk: the holding disk + * + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. + * + * This functions creates the following sysfs symlinks. + * + * - from "slaves" directory of the holder @disk to the claimed @bdev + * - from "holders" directory of the @bdev to the holder @disk + * + * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is + * passed to bd_link_disk_holder(), then: + * + * /sys/block/dm-0/slaves/sda --> /sys/block/sda + * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 + * + * The caller must have claimed @bdev before calling this function and + * ensure that both @bdev and @disk are valid during the creation and + * lifetime of these symlinks. + * + * CONTEXT: + * Might sleep. + * + * RETURNS: + * 0 on success, -errno on failure. + */ +int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) +{ + struct bd_holder_disk *holder; + int ret = 0; + + mutex_lock(&bdev->bd_disk->open_mutex); + + WARN_ON_ONCE(!bdev->bd_holder); + + /* FIXME: remove the following once add_disk() handles errors */ + if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) + goto out_unlock; + + holder = bd_find_holder_disk(bdev, disk); + if (holder) { + holder->refcnt++; + goto out_unlock; + } + + holder = kzalloc(sizeof(*holder), GFP_KERNEL); + if (!holder) { + ret = -ENOMEM; + goto out_unlock; + } + + INIT_LIST_HEAD(&holder->list); + holder->disk = disk; + holder->refcnt = 1; + + ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); + if (ret) + goto out_free; + + ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); + if (ret) + goto out_del; + /* + * bdev could be deleted beneath us which would implicitly destroy + * the holder directory. Hold on to it. + */ + kobject_get(bdev->bd_holder_dir); + + list_add(&holder->list, &bdev->bd_holder_disks); + goto out_unlock; + +out_del: + del_symlink(disk->slave_dir, bdev_kobj(bdev)); +out_free: + kfree(holder); +out_unlock: + mutex_unlock(&bdev->bd_disk->open_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(bd_link_disk_holder); + +/** + * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() + * @bdev: the calimed slave bdev + * @disk: the holding disk + * + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. + * + * CONTEXT: + * Might sleep. + */ +void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) +{ + struct bd_holder_disk *holder; + + mutex_lock(&bdev->bd_disk->open_mutex); + holder = bd_find_holder_disk(bdev, disk); + if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { + del_symlink(disk->slave_dir, bdev_kobj(bdev)); + del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); + kobject_put(bdev->bd_holder_dir); + list_del_init(&holder->list); + kfree(holder); + } + mutex_unlock(&bdev->bd_disk->open_mutex); +} +EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 0602e82a9516..f821dae101a9 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -15,6 +15,7 @@ if MD config BLK_DEV_MD tristate "RAID support" + select BLOCK_HOLDER_DEPRECATED if SYSFS help This driver lets you combine several hard disk partitions into one logical block device. This can be used to simply append one @@ -201,6 +202,7 @@ config BLK_DEV_DM_BUILTIN config BLK_DEV_DM tristate "Device mapper support" + select BLOCK_HOLDER_DEPRECATED if SYSFS select BLK_DEV_DM_BUILTIN depends on DAX || DAX=n help diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig index d1ca4d059c20..cf3e8096942a 100644 --- a/drivers/md/bcache/Kconfig +++ b/drivers/md/bcache/Kconfig @@ -2,6 +2,7 @@ config BCACHE tristate "Block device as cache" + select BLOCK_HOLDER_DEPRECATED if SYSFS select CRC64 help Allows a block device to be used as cache for other devices; uses diff --git a/fs/block_dev.c b/fs/block_dev.c index 0c424a0cadaa..7825d152634e 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -900,7 +900,7 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) bdev->bd_disk = disk; bdev->bd_partno = partno; bdev->bd_inode = inode; -#ifdef CONFIG_SYSFS +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED INIT_LIST_HEAD(&bdev->bd_holder_disks); #endif bdev->bd_stats = alloc_percpu(struct disk_stats); @@ -1092,148 +1092,6 @@ void bd_abort_claiming(struct block_device *bdev, void *holder) } EXPORT_SYMBOL(bd_abort_claiming); -#ifdef CONFIG_SYSFS -struct bd_holder_disk { - struct list_head list; - struct gendisk *disk; - int refcnt; -}; - -static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, - struct gendisk *disk) -{ - struct bd_holder_disk *holder; - - list_for_each_entry(holder, &bdev->bd_holder_disks, list) - if (holder->disk == disk) - return holder; - return NULL; -} - -static int add_symlink(struct kobject *from, struct kobject *to) -{ - return sysfs_create_link(from, to, kobject_name(to)); -} - -static void del_symlink(struct kobject *from, struct kobject *to) -{ - sysfs_remove_link(from, kobject_name(to)); -} - -/** - * bd_link_disk_holder - create symlinks between holding disk and slave bdev - * @bdev: the claimed slave bdev - * @disk: the holding disk - * - * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. - * - * This functions creates the following sysfs symlinks. - * - * - from "slaves" directory of the holder @disk to the claimed @bdev - * - from "holders" directory of the @bdev to the holder @disk - * - * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is - * passed to bd_link_disk_holder(), then: - * - * /sys/block/dm-0/slaves/sda --> /sys/block/sda - * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 - * - * The caller must have claimed @bdev before calling this function and - * ensure that both @bdev and @disk are valid during the creation and - * lifetime of these symlinks. - * - * CONTEXT: - * Might sleep. - * - * RETURNS: - * 0 on success, -errno on failure. - */ -int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) -{ - struct bd_holder_disk *holder; - int ret = 0; - - mutex_lock(&bdev->bd_disk->open_mutex); - - WARN_ON_ONCE(!bdev->bd_holder); - - /* FIXME: remove the following once add_disk() handles errors */ - if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) - goto out_unlock; - - holder = bd_find_holder_disk(bdev, disk); - if (holder) { - holder->refcnt++; - goto out_unlock; - } - - holder = kzalloc(sizeof(*holder), GFP_KERNEL); - if (!holder) { - ret = -ENOMEM; - goto out_unlock; - } - - INIT_LIST_HEAD(&holder->list); - holder->disk = disk; - holder->refcnt = 1; - - ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); - if (ret) - goto out_free; - - ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); - if (ret) - goto out_del; - /* - * bdev could be deleted beneath us which would implicitly destroy - * the holder directory. Hold on to it. - */ - kobject_get(bdev->bd_holder_dir); - - list_add(&holder->list, &bdev->bd_holder_disks); - goto out_unlock; - -out_del: - del_symlink(disk->slave_dir, bdev_kobj(bdev)); -out_free: - kfree(holder); -out_unlock: - mutex_unlock(&bdev->bd_disk->open_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(bd_link_disk_holder); - -/** - * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() - * @bdev: the calimed slave bdev - * @disk: the holding disk - * - * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. - * - * CONTEXT: - * Might sleep. - */ -void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) -{ - struct bd_holder_disk *holder; - - mutex_lock(&bdev->bd_disk->open_mutex); - - holder = bd_find_holder_disk(bdev, disk); - - if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { - del_symlink(disk->slave_dir, bdev_kobj(bdev)); - del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); - kobject_put(bdev->bd_holder_dir); - list_del_init(&holder->list); - kfree(holder); - } - - mutex_unlock(&bdev->bd_disk->open_mutex); -} -EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); -#endif - static void blkdev_flush_mapping(struct block_device *bdev) { WARN_ON_ONCE(bdev->bd_holders); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 290f9061b29a..7a4e139d24ef 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -34,7 +34,7 @@ struct block_device { void * bd_holder; int bd_holders; bool bd_write_holder; -#ifdef CONFIG_SYSFS +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED struct list_head bd_holder_disks; #endif struct kobject *bd_holder_dir; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 13b34177cc85..6831d74f2002 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -316,7 +316,7 @@ void set_capacity(struct gendisk *disk, sector_t size); int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long); long compat_blkdev_ioctl(struct file *, unsigned, unsigned long); -#ifdef CONFIG_SYSFS +#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk); void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk); #else @@ -329,7 +329,7 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) { } -#endif /* CONFIG_SYSFS */ +#endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */ dev_t part_devt(struct gendisk *disk, u8 partno); dev_t blk_lookup_devt(const char *name, int partno);
Move the block holder code into a separate file as it is not in any way related to the other block_dev.c code, and add a new selectable config option for it so that we don't have to build it without any remapped drivers selected. Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/Kconfig | 4 ++ block/Makefile | 1 + block/holder.c | 139 ++++++++++++++++++++++++++++++++++++ drivers/md/Kconfig | 2 + drivers/md/bcache/Kconfig | 1 + fs/block_dev.c | 144 +------------------------------------- include/linux/blk_types.h | 2 +- include/linux/genhd.h | 4 +- 8 files changed, 151 insertions(+), 146 deletions(-) create mode 100644 block/holder.c